Nearly all digital data is stored on magnetic media. Magnetic media includes magnetic tape, hard drives, and floppy disks. Magnetic tape is a medium for magnetic recording, made of a thin layer of magnetizable nanoparticles coated onto one side of a long, narrow substrate of BoPET (Biaxially-oriented polyethylene terephthalate), which is a polyester film made from stretched polyethylene terephthalate (PET), which has the common trade name of MYLAR.